verbatim): This proposal is designed to test hypotheses related to gene transfer of adenylyl cyclases to modulate agonist-specific cyclic AMP generation of cardiovascular cells. Adenylyl cyclase (AC) expression appears to be the limiting component for maximal generation of cyclic AMP by agonists, such as beta-adrenergic agonists, that promote such generation. Our preliminary data in cardiac myocytes demonstrate that increased expression of AC-6 (one of the ten isoforms of this enzyme) dramatically enhances beta-adrenergic response without enhancing response to several other stimulatory agonists but while retaining and perhaps enhancing ability of the muscarinic cholinergic agonist carbachol and endothelin to inhibit cAMP generation. We propose to test the impact of increasing expression of AC-6 (using an adenoviral construct) on cyclic AMP formation in key cardiovascular cells, endothelial cells, and vascular smooth muscle cells, in addition to cardiac myocytes, and in particular, to characterize the patterns of stimulation and inhibition of AC-6 in such cells. In other Aims we will test hypotheses developed to explain the selective enhancement of beta-adrenergic response by overexpressed AC-6: 1) preferential coupling of beta-adrenergic receptors to AC-6 compared to certain other AC isoforms (by testing impact of adenoviral transfer of AC-4 and AC-8, each with its own unique pattern of regulation, to cardiac cells); 2) inhibitory regulation of AC-6 that may contribute to patterns of receptor stimulation of cAMP synthesis; and 3) targeting of AC isoforms to membrane domains enriched in certain receptors and other components that regulate cyclic AMP formation and action. Results of these studies should yield new information regarding the role of AC expression as a limiting component in cAMP formation, the impact of gene transfer of AC isoforms to several key cardiovascular cells, and provide evidence that this approach may provide a novel means to alter signaling in such cells.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL063885-02
Application #
6390571
Study Section
Cardiovascular and Pulmonary Research A Study Section (CVA)
Program Officer
Skarlatos, Sonia
Project Start
2000-09-01
Project End
2004-08-31
Budget Start
2001-09-01
Budget End
2002-08-31
Support Year
2
Fiscal Year
2001
Total Cost
$304,000
Indirect Cost
Name
University of California San Diego
Department
Pharmacology
Type
Schools of Medicine
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
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Swaney, James S; Roth, David M; Olson, Erik R et al. (2005) Inhibition of cardiac myofibroblast formation and collagen synthesis by activation and overexpression of adenylyl cyclase. Proc Natl Acad Sci U S A 102:437-42
Insel, Paul A; Head, Brian P; Ostrom, Rennolds S et al. (2005) Caveolae and lipid rafts: G protein-coupled receptor signaling microdomains in cardiac myocytes. Ann N Y Acad Sci 1047:166-72
Head, Brian P; Patel, Hemal H; Roth, David M et al. (2005) G-protein-coupled receptor signaling components localize in both sarcolemmal and intracellular caveolin-3-associated microdomains in adult cardiac myocytes. J Biol Chem 280:31036-44
Ostrom, Rennolds S; Bundey, Richard A; Insel, Paul A (2004) Nitric oxide inhibition of adenylyl cyclase type 6 activity is dependent upon lipid rafts and caveolin signaling complexes. J Biol Chem 279:19846-53
Tang, Chih-Min; Insel, Paul A (2004) GPCR expression in the heart; ""new"" receptors in myocytes and fibroblasts. Trends Cardiovasc Med 14:94-9
Ostrom, Rennolds S; Insel, Paul A (2004) The evolving role of lipid rafts and caveolae in G protein-coupled receptor signaling: implications for molecular pharmacology. Br J Pharmacol 143:235-45
Ostrom, Rennolds S; Naugle, Jennifer E; Hase, Miki et al. (2003) Angiotensin II enhances adenylyl cyclase signaling via Ca2+/calmodulin. Gq-Gs cross-talk regulates collagen production in cardiac fibroblasts. J Biol Chem 278:24461-8
Bundey, Richard A; Insel, Paul A (2003) Quantification of adenylyl cyclase messenger RNA by real-time polymerase chain reaction. Anal Biochem 319:318-22
Insel, Paul A; Kirstein, Shelli L (2003) Naturally occurring variants in catecholamine receptor genes. Auton Autacoid Pharmacol 23:228-30

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